Accuracy of An Algorithm Using Motion Data Of Five Wearable IMU Sensors For Estimating Lifting Duration And Lifting Risk Factors

Abstract

The objective of this study was to assess the accuracy of an algorithm for processing data from five inertial measurement unit (IMU) sensors for measuring the vertical distance (V) and horizontal distance (H) of two handed lifting, trunk flexion angle (T) and lifting duration (LD). The sensors were placed on five body segments including the left wrist, right wrist, upper arm of the dominant hand, upper back, and thigh of the dominant leg. A laboratory-grade optical motion capture system was used as the ground truth for the assessment. Data were collected on ten subjects that performed 12 two-handed lifting tasks varying in height of the hands and horizontal distance between the body and the lifted object. Results showed that the algorithm performed well for determining the LD (~1 sec error) and T (~2° error). The average errors for V and H were about 33 and 6.5 cm, respectively.